Reproduced in build 200708200000.

To reproduce the bug:
- create a new XSLT Service;
- delete the XSL file;
- open transformmap.xml in Source Editor;
- remove service description from transformmap.xml as follows:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<transformmap xmlns='http://xml.netbeans.org/schema/transformmap' xmlns:ns1="http://j2ee.netbeans.org/wsdl/newWSDL">
       
<!--
       <service partnerLinkType="ns0:plt1" roleName="role1">
           <operation opName="operation0">
               <transform result="" source="" file="">
                   <param name="param1" type="t1"></param>
                   <param name="param2" type="t2"></param>
               </transform>
           </operation>
           <operation opName="operation1">
               <invoke roleName="role2" partnerLinkType="ns0:plt2" inputVariable=""  outputVariable=""/>
           </operation>
       </service>

-->
</transformmap>

- create the same XSLT Service.

java.lang.NullPointerException
	at org.netbeans.modules.xslt.tmap.util.Util.getTransformationDescriptor(Util.java:224)
	at org.netbeans.modules.xslt.core.context.MapperContextImpl.getValidationMessage(MapperContextImpl.java:656)
	at org.netbeans.modules.xslt.mapper.model.ModelBridge.checkErrors(ModelBridge.java:94)
	at org.netbeans.modules.xslt.mapper.model.SchemaModelBridge.onModelChanged(SchemaModelBridge.java:42)
	at org.netbeans.modules.xslt.mapper.model.ModelBridge$UpdateTimer$1.actionPerformed(ModelBridge.java:71)
	at javax.swing.Timer.fireActionPerformed(Timer.java:271)
	at javax.swing.Timer$DoPostEvent.run(Timer.java:201)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:177)
	at java.awt.Dialog$1.run(Dialog.java:1039)
	at java.awt.Dialog$3.run(Dialog.java:1091)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.Dialog.show(Dialog.java:1089)
	at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:812)
	at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:846)
	at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:834)
	at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:82)
	at org.openide.util.Mutex.doEventAccess(Mutex.java:1201)
	at org.openide.util.Mutex.readAccess(Mutex.java:220)
	at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:819)
	at java.awt.Component.show(Component.java:1419)
	at java.awt.Component.setVisible(Component.java:1372)
	at java.awt.Window.setVisible(Window.java:801)
	at java.awt.Dialog.setVisible(Dialog.java:979)
	at org.openide.loaders.TemplateWizard.instantiateImpl(TemplateWizard.java:480)
	at org.openide.loaders.TemplateWizard.instantiate(TemplateWizard.java:359)
	at org.netbeans.modules.project.ui.actions.NewFile.doPerform(NewFile.java:125)
	at org.netbeans.modules.project.ui.actions.NewFile.access$200(NewFile.java:58)
	at org.netbeans.modules.project.ui.actions.NewFile$PopupListener.actionPerformed(NewFile.java:318)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
	at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
	at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1216)
	at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1257)
	at java.awt.Component.processMouseEvent(Component.java:6038)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
	at java.awt.Component.processEvent(Component.java:5803)
	at java.awt.Container.processEvent(Container.java:2058)
	at java.awt.Component.dispatchEventImpl(Component.java:4410)
	at java.awt.Container.dispatchEventImpl(Container.java:2116)
	at java.awt.Component.dispatchEvent(Component.java:4240)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
	at java.awt.Container.dispatchEventImpl(Container.java:2102)
	at java.awt.Window.dispatchEventImpl(Window.java:2429)
	at java.awt.Component.dispatchEvent(Component.java:4240)
...